scholarly journals The implications of gamma-ray photons from LHAASO on Lorentz symmetry

2021 ◽  
Author(s):  
Yi 凌意 Ling ◽  
Yu xuan Liu ◽  
Sai Wang ◽  
Meng-He Wu
Keyword(s):  
Survival Probability ◽  
High Energy Physics ◽  
Gamma Ray ◽  
Threshold Value ◽  
Mean Free Path ◽  
High Energy ◽  
Lorentz Symmetry ◽  
Symmetry Violation ◽  
High Energy Level ◽  
Creative Commons

Abstract The Large High Altitude Air Shower Observatory (LHAASO) has reported the measurement of photons with high energy up to 1.42 PeV from 12 gamma-ray sources. We are concerned with the implications of LHAASO data on the fate of Lorenz symmetry at such high energy level, thus we consider the interaction of the gamma ray with those photons in cosmic microwave background (CMB), and compute the optical depth, the mean free path as well as the survival probability for photons from all these gamma-ray sources. Employing the threshold value predicted by the standard special relativity, it is found that the lowest survival probability for observed gamma ray photons is about 0.60, which is a fairly high value and implies that abundant photons with energy above the threshold value may reach the Earth without Lorentz symmetry violation. We conclude that it is still far to argue that the Lorentz symmetry would be violated due to the present observations from LHAASO. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Article funded by SCOAP3 and published under licence by Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Science and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.

scholarly journals Annihilation diagram contribution to charmonium masses

2021 ◽  
Author(s):  
Renqiang 张仁强 Zhang ◽  
Ying Chen ◽  
Wei Sun ◽  
Zhaofeng Liu ◽  
Ming Gong ◽  
...  
Keyword(s):  
High Energy Physics ◽  
Charm Quark ◽  
High Energy ◽  
Mass Shift ◽  
Unitary Theory ◽  
Charm Quarks ◽  
Creative Commons ◽  
Anisotropic Lattices ◽  
Modern Physics ◽  
Academy Of Sciences

Abstract In this work, we generate gauge configurations with $N_f=2$ dynamical charm quarks on anisotropic lattices. The mass shift of $1S$ and $1P$ charmonia owing to the charm quark annihilation effect can be investigated directly in a manner of unitary theory. The distillation method is adopted to treat the charm quark annihilation diagrams at a very precise level. For $1S$ charmonia, the charm quark annihilation effect almost does not change the $J/\psi$ mass, but lifts the $\eta_c$ mass by approximately 3-4 MeV. For $1P$ charmonia, this effect results in positive mass shifts of approximately 1 MeV for $\chi_{c1}$ and $h_c$, but decreases the $\chi_{c2}$ mass by approximately 3 MeV. We have not obtain a reliable result for the mass shift of $\chi_{c0}$. In addition, it is observed that the spin averaged mass of the spin-triplet $1P$ charmonia is in a good agreement with the $h_c$, as expected by the non-relativistic quark model and measured by experiments. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Article funded by SCOAP3 and published under licence by Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Science and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.

scholarly journals The Unsolved Problem of Stellar Origins

1996 ◽  
Vol 169 ◽  
pp. 533-549
Author(s):  
Charles J. Lada
Keyword(s):  
Twentieth Century ◽  
Science Fiction ◽  
High Energy Physics ◽  
Gamma Ray ◽  
High Energy ◽  
Giant Molecular Clouds ◽  
Observational Astronomy ◽  
History Of ◽  
Large Telescopes ◽  
The Universe

We now stand at the threshold of the 21st century having witnessed perhaps the greatest era of astronomical discovery in the history of mankind. During the twentieth century the subject of astronomy was revolutionized and completely transformed by technology and physics. Advances in technology that produced radio astronomy, infrared astronomy, UV, X and γ ray astronomy, large telescopes on the ground, in balloons, aircraft and space coupled with advances in nuclear, atomic and high energy physics forever changed the way in which the universe is viewed. Indeed, it is altogether likely that future historians of science will consider the twentieth century as the Golden Age of observational astronomy. As a measure of how far we have come in the last 100 years, recall that at the turn of this century the nature of spiral nebulae and of the Milky Way itself as an island universe were not yet revealed. The expansion of the universe and the microwave background were not yet discovered and exotic objects such as quasars, pulsars, gamma-ray bursters and black holes were not even envisioned by the most imaginative authors of science fiction. The interstellar medium, with its giant molecular clouds, magnetic fields and obscuring dust was unknown. Not even the nature of stars, these most fundamental objects of the astronomical universe, was understood.

Study on Thallium Bromide Radioactive Detector

2019 ◽  
Vol 5 (2) ◽  
Author(s):  
He Li-xia ◽  
Hao Xiao-yong ◽  
He Gao-kui
Keyword(s):  
High Energy Physics ◽  
Gamma Ray ◽  
Detection Efficiency ◽  
Nuclear Material ◽  
High Energy ◽  
Device Fabrication ◽  
Signal Acquisition ◽  
X Ray ◽  
Thallium Bromide ◽  
And Performance

Thallium bromide (TlBr) is a compound semiconductor material, which can be used for X-ray and gamma-ray detectors and can be used at room temperature. It has excellent physical properties, high atomic number and density, wide bandgap (B = 2.68 eV), and low ionization energy. Compared with other X-ray and gamma-ray detection materials, TlBr devices have high detection efficiency and excellent energy resolution performance. So TlBr is suitable for housing in small tubes or shells, and it can be widely used in nuclear material measurement, safeguards verification, national security, space high-energy physics research, and other fields. Based on the fabrication of TlBr prototype detector, this paper focuses on the device fabrication and signal acquisition technology. Gamma-ray spectrum measurements and performance tests are carried out with AM-241 radioactive source. The results show that the special photoelectric peak of 59.5 keV is clearly visible, and the optimal resolution is 4.15 keV (7%).

scholarly journals Gravitational waves from cosmic strings after a first-order phase transition

2021 ◽  
Author(s):  
Ligong Bian ◽  
Ruiyu 瑞雨 Zhou
Keyword(s):  
Phase Transition ◽  
Order Phase Transition ◽  
High Energy Physics ◽  
Cosmic Strings ◽  
High Energy ◽  
Wave Radiation ◽  
First Order ◽  
Creative Commons ◽  
First Order Phase Transition ◽  
First Order Phase

Abstract We study the possibility of probing high scale phase transitions that are unaccessible by LIGO. Our study shows that the stochastic gravitational-wave radiation from cosmic strings that are formed after the first-order phase transition can be detected by space-based interferometers when the phase transition temperature is $T_n\sim \mathcal{O}(10^{8-11})$ GeV. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Article funded by SCOAP3 and published under licence by Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Science and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.

scholarly journals Lattice calaulation of χc0→ 2γ decay width

2022 ◽  
Author(s):  
Zuoheng Zou ◽  
Yu Meng ◽  
Chuan 刘川 Liu
Keyword(s):  
Lattice Qcd ◽  
Decay Width ◽  
High Energy Physics ◽  
Form Factors ◽  
Statistical Error ◽  
High Energy ◽  
Creative Commons ◽  
Modern Physics ◽  
Gamma Decay ◽  
Academy Of Sciences

Abstract We perform a lattice QCD calculation of the $\chi_{c0} \rightarrow 2\gamma$ decay width using a model-independent method which does not require a momentum extrapolation of the corresponding off-shell form factors. The simulation is performed on ensembles of $N_f=2$ twisted mass lattice QCD gauge configurations with three different lattice spacings. After a continuum extrapolation, the decay width is obtained to be $\Gamma_{\gamma\gamma}(\chi_{c0})=3.65(83)_{\mathrm{stat}}(21)_{\mathrm{lat.syst}}(66)_{\mathrm{syst}}\, \textrm{keV}$. Albeit this large statistical error, our result is compatible with the experimental results within 1.3$\sigma$. Potential improvements of the lattice calculation in the future are also discussed. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Article funded by SCOAP3 and published under licence by Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Science and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.

scholarly journals P-wave $\Omega_{b}$ states: masses and pole residues

2021 ◽  
Author(s):  
Yong-Jiang XU ◽  
Yong-Lu Liu ◽  
Ming-Qiu Huang
Keyword(s):  
High Energy Physics ◽  
High Energy ◽  
Lhcb Collaboration ◽  
P Wave ◽  
Creative Commons ◽  
Chinese Academy Of Sciences ◽  
Modern Physics ◽  
The Masses ◽  
Academy Of Sciences ◽  
Energy Physics

Abstract In this paper, we consider all P-wave $\Omega_{b}$ states represented by interpolating currents with a derivative and calculate the corresponding masses and pole residues with the method of QCD sum rule. Due to the large uncertainties in our calculation compared with the small difference in the masses of the excited $\Omega_{b}$ states observed by the LHCb collaboration, it is necessary to study other properties of the P-wave $\Omega_{b}$ states represented by the interpolating currents investigated in the present work in order to have a better understanding about the four excited $\Omega_{b}$ states observed by the LHCb collaboration. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Article funded by SCOAP3 and published under licence by Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Science and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.

Investigation of parameters of new MAPD-3NM silicon photomultipliers

2022 ◽  
Vol 17 (01) ◽  
pp. C01001
Author(s):  
F. Ahmadov ◽  
G. Ahmadov ◽  
R. Akbarov ◽  
A. Aktag ◽  
E. Budak ◽  
...  
Keyword(s):  
High Energy Physics ◽  
Gamma Ray ◽  
Detection Efficiency ◽  
High Energy ◽  
Efficiency Gain ◽  
Space Application ◽  
Silicon Photomultipliers ◽  
Photon Detection ◽  
Photon Detection Efficiency ◽  
Energy Physics

Abstract In the presented work, the parameters of a new MAPD-3NM-II photodiode with buried pixel structure manufactured in cooperation with Zecotek Company are investigated. The photon detection efficiency, gain, capacitance and gamma-ray detection performance of photodiodes are studied. The SPECTRIG MAPD is used to measure the parameters of the MAPD-3NM-II and scintillation detector based on it. The obtained results show that the newly developed MAPD-3NM-II photodiode outperforms its counterparts in most parameters and it can be successfully applied in space application, medicine, high-energy physics and security.

scholarly journals Improved Bounds on Lorentz Symmetry Violation from High-Energy Astrophysical Sources

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 688
Author(s):  
Brett Altschul
Keyword(s):  
Lorentz Violation ◽  
High Energy ◽  
Lorentz Symmetry ◽  
Symmetry Violation ◽  
Inverse Compton ◽  
Γ Ray

Observations of the synchrotron and inverse Compton emissions from ultrarelativistic electrons in astrophysical sources can reveal a great deal about the energy–momentum relations of those electrons. They can thus be used to place bounds on the possibility of Lorentz violation in the electron sector. Recent γ-ray telescope data allow the Lorentz-violating electron cνμ parameters to be constrained extremely well, so that all bounds are at the level of 7×10−16 or better.

scholarly journals EuPRAXIA Conceptual Design Report

2020 ◽  
Vol 229 (24) ◽  
pp. 3675-4284
Author(s):  
R. W. Assmann ◽  
M. K. Weikum ◽  
T. Akhter ◽  
D. Alesini ◽  
A. S. Alexandrova ◽  
...  
Keyword(s):  
Conceptual Design ◽  
High Energy Physics ◽  
Gamma Ray ◽  
Knowledge Exchange ◽  
High Energy ◽  
Particle Accelerator ◽  
Research Infrastructure ◽  
The European Union ◽  
Horizon 2020 ◽  
Energy Frontier

AbstractThis report presents the conceptual design of a new European research infrastructure EuPRAXIA. The concept has been established over the last four years in a unique collaboration of 41 laboratories within a Horizon 2020 design study funded by the European Union. EuPRAXIA is the first European project that develops a dedicated particle accelerator research infrastructure based on novel plasma acceleration concepts and laser technology. It focuses on the development of electron accelerators and underlying technologies, their user communities, and the exploitation of existing accelerator infrastructures in Europe. EuPRAXIA has involved, amongst others, the international laser community and industry to build links and bridges with accelerator science — through realising synergies, identifying disruptive ideas, innovating, and fostering knowledge exchange. The Eu-PRAXIA project aims at the construction of an innovative electron accelerator using laser- and electron-beam-driven plasma wakefield acceleration that offers a significant reduction in size and possible savings in cost over current state-of-the-art radiofrequency-based accelerators. The foreseen electron energy range of one to five gigaelectronvolts (GeV) and its performance goals will enable versatile applications in various domains, e.g. as a compact free-electron laser (FEL), compact sources for medical imaging and positron generation, table-top test beams for particle detectors, as well as deeply penetrating X-ray and gamma-ray sources for material testing. EuPRAXIA is designed to be the required stepping stone to possible future plasma-based facilities, such as linear colliders at the high-energy physics (HEP) energy frontier. Consistent with a high-confidence approach, the project includes measures to retire risk by establishing scaled technology demonstrators. This report includes preliminary models for project implementation, cost and schedule that would allow operation of the full Eu-PRAXIA facility within 8—10 years.

Sign in / Sign up

Export Citation Format

Share Document